Combination lock



FIG. 1 is a top plan view of a combination lock embodying my new design;

FIG. 2 is a side elevational view as seen from the right side of FIG. 1, the appearance of the opposite side being similar;

FIG. 3 is a front elevational view as seen from the bottom of FIG. 1;

FIG. 4 is a rear elevational view as seen from the top of FIG. 1; and

FIG. 5 is a bottom plan view. 

The ornamental design for a combination lock, as shown and described. 